Formula Builder

Why not use Python to calculate Maths formulas

Maths symbols used
Add + subtract - divide / multiply *

User inputs into the program
var1=int(input("Type the width number only"))#This puts a whole number #the user typed into a #variable called var1
var2=float(input("Type a decimal or negative number"))#This puts a decimal or #negative number the user #typed into a variable called #var2

Perimeter of a square example
We know that the perimeter of a square is 4 times the length of one side.
Copy the code and paste it into a new Python file to try it.
print("Welcome to my perimeter of a square program")
oneside=int(input("Please type the length of one side of the square as a number only"))
units=input("Please type in the units that you are using eg cm mm inches etc")
print("The perimeter of your square is",oneside,units)
Line 2 and 3 collect data from the user and store this data in variables called oneside and units.
Line 4 multiplies oneside by 4 and puts the new total back into the variable called oneside.
Line 5 outputs the total inside oneside and the units inside the variable called units 
back to the user.

Try inputting 22.5 cm 
Why does it fail?

Now try creating your own formulas in Formula Builder2